Selecting pipe is among the most challenging tasks a public works professional can face—even more so than fielding angry phone calls after a water-main burst. There exists a staggering array of materials (plastic, iron, clay, concrete, and others), diameters (ranging from sizes big enough to ride a horse through, to pipes barely big enough for a mouse to scamper in), accessories (like liners and joints), and other factors.

The answer: Carefully.

The wrong kind of pipe can get you in trouble—for instance, using material with improper corrosion resistance for a sewer could create a messy breakdown. Pick a pipe that's not up to code, and you risk having a stern-faced bureaucrat knocking on your door, and maybe incurring a fine. If your diameter's too small, your system won't be able to handle the load your municipality requires.

How do you choose?

Fortunately, there are nearly as many different helpful pipe resources out there as there are types of pipe associations, publications, manufacturers'guidelines, and others. With the pipe selection chart on page 42 and page 43, PUBLIC WORKS is adding to the list of helpful tools—it includes different pipe materials, varieties, diameters, and Web sites you can visit for further assistance.

Posing The Questions

If you're building a house, you can't head out to Home Depot for supplies until you know everything about the house and the ground around it—how many people are going to live there, what type of ground the foundation will sit on, what kind of weather the area has, etc. Installing pipe is a lot like that—answering a number of questions at the outset will get you started off on the right foot.

What's the job? If you're planning a sewer installation, for instance, you're a lot more likely to use large-diameter concrete pipe. Copper, not so much.

What kind of demand are you placing on it? Think about existing conditions in your municipality, but also anticipate future growth—you don't want to put in 56-inch concrete pipe, only to have an explosion in population and area businesses necessitate an upgrade only a few years down the road.

What's your budget? Surprise, surprise—you don't have an unlimited pile of cash to draw from. However, you might also be surprised that your engineers and contractor can come up with an economical solution to your pipe problem—and spending a little extra money now might save tons in the long run in terms of reducing maintenance and avoiding replacement.

What does your jobsite look like? Corrosive soil can affect certain types of pipe. So can freeze-thaw conditions. Know your ground before you put the pipe into it.